Cellulosic composition of matter containing ethyl chloro-carbonate



(1 INITIIIL FLEXIBILITY or %CONIBUS TION TIME.

s. J. CARROLL 1,826,690

- CELL-ULOSIC COMPOSITION OF MATTER CONTAINING ETH YL CHLORO-CARBONATE Filed Aug- 50. 1929 .b-DRYS MAINTI-UNS FLEXIBILITY RT 6 'PLFISTICIZER.

gmmlo'o Ewyari LI Barr E11 Patented Oct, 6, 1931 UNITED STATES P ATENT OFFICE STEWART J'. CARROLL, OF ROCHESTER,

NEW YORK, ASSIGNOR TO EASTMAN KODAK COMPANY, 01' nocnnsrnn, NEW YORK, A CORPORATION on NEW YORK CELLULOSIC COMPOSITION OF MATTER CONTAINING ETHYL CHLOBO-CARCBONATE Application filed August 3t), 1929. Serial No. 389,453.

This invention relates to compositions of matter in which cellulose derivatives, such as cellulose acetate, cellulose nitrate or cellulose ether, and combined or mixed with other substances, such as acompatible plasticizer, and a common solvent for both, with or without other useful addition agents, so that the resulting product'will have properties such as will make the composition highly advantageous vfor use in the plastic and analogous arts, such, for instance, as the manufacture of wrapping sheets, photographic film, artificial silk, varnishes or lacquers, and the like- One object of this invention is to produce a composition of matter which may lee-madeinto permanently transparent, strong and flexible sheets or films of desired thinness which are substantially waterproof, are unaffected by ordinary photographic fluids and possess the desired properties of afsupport for sensitive photographic coatings. Another object of my invention is to produce a composition which is capable 'of easy and convenient manipulation in the plastic and analogous arts, such as in the manufacture.

have been known for decades it has also been known that to utilize them in the various plastic arts it is necessary to mix therewith such plast'icizing or conditioning agents as camphor, castor oil, triphenyl phosphate, monochlornaphthalene or the like. Certain of these andtother addition agents are also added for the purpose of reducing the inflammability of the product. Plastic inducing agents, such asthe higher alcohols and their esters, are sometimes also added. Similarly addition compounds of various kinds have been employed to increase flexibility, transparency, toughness and other properties derivative and plasticizer.

which will enhance the value of the resulting product. Addition products for the same or similar purposes are also added to cellulose acetates, nitrates and ethers to prepare them for use-in the other plastic arts, suchas in the manufacture of lacquers, varnishes, artificial silk filaments, moulded compounds and the like. While the plasticizers or other addition agents heretofore discovered have had their utility in the art, the increasing' use to which cellulose derivatives have been put and the increasing number of desirable properties required of the cellulose 4 derivative for most purposes has made the discovery of new and economical plasticizers or other addition agents'a matter of considerable importance to the art. v v

. I have discovered that valuable properties may be induced-in and/ or contributed to compositions containing cellulose,- derivatives, such as cellulose acetate, by adding thereto the plasticizing compound ethyl-chloro-carbonate in the presence of-a" solvent, such as acetone, which-will dissolve both the cellulose .This plasticizer is a liquid at ordinary atmospheric temperature and has the structural formula of It is compatiblewith cellulose derivatives and particularly compatible with cellulose acetate in the percentages hereinafter glven.

.- It is not an expensive compound and not particularly difficult to produce, or obtain upon the open market. The particularly useful properties which it induces in or contributes to a cellulosic composition containing it are hereinafter enumerated.

In order that those skilled in this art may better understand my invention I would state, by way of illustration, that for the manufacture of photographic film or other sheets my new composition of matter may be compounded as follows: 100 parts of acetone soluble cellulose acetate i. e. cellulose acetate containing radical, approximately, is dissolved with stirring at atmospheric temperature in 300 to 500 parts, preferably 400 parts, by weight, I

from 36% to 42% acetyl Inn of acetone. To this solution may be added from 10 to 50 parts by weight, of ethylchloro-carbonate, it being found preferable to employ approximately partsthereof. Within the limits stated, the amount of plasticizer may be decreased or increased, de pending upon whether it is desired to decrease or increase, respectively, the properties which this plasticizer contributes to the newsprint. Such film is tough and flexible lulose acetate and this plasticizer. On the horizontal axis is indicated the various per as shown by the fact that it will withstand many folds upon a modified Schopper fold tester (commonly used for such purposes) without breaking and that even after being subjected for 51 days to air maintained at a temperature of 65 C. the film still maintains flexibility, demonstrating that the film will withstand ordinary usa e satisfactorily for many years, whereas a %lm formed from a mere solution of cellulose acetate in acetone or other similar solvent is brittle and fragile after being subjected to the same treatment for as little as thirty days or even a lesser time. geous properties of a product produced from my new composition is considerably in excess of that of products produced with what have previously been regarded as the better plasticizers.

Other similar solvents (instead of ace-- tone) which are compatible with the cellulose acetate and my new plasticizer may also occur to those skilled in this art. In like manner this plasticizer may be compounded with other single organic esters of cellulose, such as cellulose propionate, butyrate and the like, or with mixed organic and/or inorganic esters, such as cellulose aceto-stearate, aceto-malate, or cellulose nitro-acetate, or

with the cellulose ethers, a suitable solvent which will dissolve both the celluldsic derivative and the plasticizer'being employed.

The accompanying drawing, forming a part of this application, clearly illustrates the particular advantages of employing my novel plasticizer in the plastic arts. In this drawing there are plotted lines .or\curves graphically depicting the properties of filn'ri produced om a composition containing celcentages of my plasticizer that may be employed with the cellulosic derivative, this per-Q The sum total of the above advanta-r reeaeeo centage being given in parts added to the cellulose derivatlve rather than parts of the composition; for instance, 30 parts plasticizer added to 100 parts cellulose acetate is denoted'as 30% plasticizer added. On the ver-.

same column (a) at (b) on the right is indicated the length of time in days that the film will maintain flexibility when subjected to air kept at a temperature of 65 C. The

curve (A) depicts initial flexibility of the film, the curve (B) depicts the ability of the film to maintain flexibility and the curve (0) depicts the rate of combustion of the film-all with various percentages of my novel plasticizer and all as compared to the respective v properties of a film produced from a solution of cellulose acetate in acetone and a hypothetical inert material substituted for the plasticizer as denoted by curve (D) indicatin unity of 100% and30 days for (a) and (b It will thus be noted that my novel plasticizer has the faculty of giving, to a product produced therefrom, good initial flexibility and a low combustion rate, and that the product maintains its flexibility quite well. The preferred percentage of my plasticizer which it is desirable to employ to contribute any articular property to the final product will lieobvious from an inspection of this drawing; the best percentage to employ will depend upon which property it is desired'to feature most in the final product.

Inasmuch as 'my above described composition of matter is quite useful in the production of. films and sheets it will be apparent that my new plasticizer 'may also be employed with advantage in the other branches of the .plastic art. For instance,'my above described composition of matter may be employed in the manufacture of artificial silk by the dr spinning method. With the proper coagalhting bath it may also be employed for wet spinning. It may be-desired toemploy a composition of different viscosity or evaporation characteristics but this is a mere matter of changing the solvent proportion or adding evaporation retardants such as triacetin or other high or intermediate boiling constituents, as'has been well known in the art for more than a decade. My novel plasticizer may also be employed with advantage in connection with a number of the known lacquer and varnish formulae with which it may be found to be compatible. In such cases the plasticizer is usually first put into solution with the cellulose derivative solution and if non-solvents are added for the purpose of cheapening the composition they are added g 15 .50 parts, by weight, of ethyl-chloro carbonate.

4. A composition of matter comprising 100 parts of cellulose acetate and approximately 30 parts, by. Weight, of ethyl-chloro-carbon- Z0 ate.

Signed at Rochester, New York, this 27th day of August, 1929.

STEWART J. CARROLL 

